This application claims the priority of German patent document DE 10 2007 010 349.4, filed Mar. 3, 2007, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a valve control unit for a ram jet propulsion system, and to a guided missile having such a valve control unit.
Valve control units of the generic type are used for guided missiles. As a function of signals obtained from sensors, such as position and speed sensors, they control a fuel flow rate for propelling the guided missile.
The very high temperatures that can occur in the interior of the guided missile as a result of a power unit burn, can cause thermal problems in the electronic control system of the guided missile. In addition, the electric connection from the valve control unit to the electronic system requires considerable cable lengths, which may result in electromagnetic compatibility problems. Under certain circumstances, both of these problems may impair reliable operation of the guided missile.
One object of the present invention to provide an improved valve control unit which avoids the above-mentioned disadvantages.
This and other objects and advantages are achieved by the valve control unit according to the invention, in which virtually all functions are centralized in a simple manner (specifically, without any high-expenditure constructional change of a guided missile), because an intermediate structure of the power unit is present anyway. In addition, it becomes possible to clearly reduce the contact surfaces of the mechanical interfaces, so that the unit according to the invention is housed in a thermally insulated manner, particularly by air gap insulation, which is particularly suitable for thermal insulation and also saves material. The electronic system is arranged inside the intermediate structure of the power unit, together with the mechanical valve assembly.
Another advantage of the invention is that it minimizes external functions, which in turn permits a reduction of data transmission systems.
In addition, the valve control unit according to the invention is very robust and mounting-friendly, since a very compact unit is mounted in the guided missile. The latter can also easily be tested as a result of the invention.
In an advantageous embodiment of the valve control unit according to the invention, the valve assembly is embedded in a constructional body, which reliably protects the mechanical, electrical and electromechanical components of the valve control unit, which can easily be preassembled. The constructional body with its components can be accommodated in the guided missile in a few mounting steps.
It is particularly advantageous for the valve assembly to be embedded in one or more recesses of the constructional body, with the constructional body being designed as a molded body. As a result, the components can be fixed easily and reliably; and, on the other hand, the recesses form air chambers which promote a thermal insulation because they are not in a direct contact with thermally heated parts of the missile. In particular, a very good thermal protection is obtained when the constructional body is equipped with a housing unit having a housing cover forming an air insulation gap. The housing cover prevents direct heating of the components, and allows the components to be accessible when the housing cover is removed.
In a further preferred embodiment of the invention, the valve control unit comprises an electromotive drive, particularly having a servomotor which is connected with a threaded spindle. A spindle gearing part provided on the threaded spindle can be displaced in the longitudinal direction of the threaded spindle and is connected by means of a lever element with a valve shaft. The latter defining a 90° angle with respect to the axis of the spindle drive. The threaded spindle—servo motor solution having the lever arm permits a very precise apportioning of the fuel quantity. Very rapid changes of the fuel quantity controlled by the valve can also be implemented. Furthermore, this construction provides a very space-saving arrangement, so that it can also be used if the diameter of the guided missile is relatively small.
The flying precision of the guided missile can be improved by providing an electronic control unit that comprises a controlling part having a desired phase value unit, a correction controller and an error detection unit for polar values. In this case, the desired phase value unit is fed at its input, on the one hand, with polar current and/or voltage commands and, on the other hand, with a correction signal of the correction controller. The correction controller is connected with the error detection unit, and the error detection unit is supplied with desired and actual values. Corrected desired phase values can be fed to a phase current controller, which considerably improves the controlling characteristics of the controlling function of the valve control unit.
It is also advantageous that the electronic control unit is equipped with a sensor interface with a signal processing unit that includes a semiconductor bridge circuit for controlling a driving motor, and for controlling fuel quantity required for the propulsion, in turn, the semiconductor bridge circuit is also housed in the compact control unit, so that only external sensors have to be connected at the sensor interface in order to measure, for example, a pressure in a combustion chamber.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.